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Finding the Fourth Proportional to 77.80, 116.37 and 57.31

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Solution

The fourth proportional to 77.80, 116.37 and 57.31 is: 85.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.80 : 116.37 = 57.31 : x
  2. Step 2: Convert to fraction form
    77.80/116.37 = 57.31/x
  3. Step 3: Cross multiply
    77.80x = 116.37 × 57.31
  4. Step 4: Simplify right side
    77.80x = 6,669.16
  5. Step 5: Solve for x
    x = 6,669.16/77.80
  6. Step 6: Final answer
    x = 85.72

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.